Some of the "big economies of the future" are the most vulnerable to the effects of climate change, according to a new study published today.

UK consultancy Maplecroft identified Bangladesh and India as the two countries facing the greatest risks to their populations, ecosystems and business environments after ranking 170 countries based on their exposure to climate-related natural disasters and their social, economic and political ability to adapt to a changing climate.

According to Maplecroft, the countries facing the greatest risks are characterised by high levels of poverty, dense populations, exposure to climate-related events and reliance on flood- and drought-prone agricultural land.

Bangladesh ticks most of these boxes and the report warns that rising climate risks could hit foreign investment into the country, undermining the driving force behind economic growth of 88 per cent between 2000 and 2008.

Similarly, the report warned that India's massive population and increasing demand for scarce resources made it particularly sensitive to climate change.

Other Asian countries attracting high levels of foreign investment such as the Philippines, Vietnam and Pakistan were also classified as facing 'extreme risk' from climate change, while industrial giants China, Brazil and Japan are listed as 'high risk'.

"This means organisations with operations or assets in these countries will become more exposed to associated risks, such as climate-related natural disasters, resource security and conflict," said Dr Matthew Bunce, principal environmental analyst at Maplecroft. "Understanding climate vulnerability will help companies make their investments more resilient to unexpected change."

Some states were not listed because of a lack of data, including North Korea and small island states such as the Maldives that are vulnerable to rising sea l evels.

Wealthy European nations made up the majority of low risk countries, with Norway, Finland, Iceland, Ireland, Sweden and Denmark deemed to face the lowest risk of climate-related disruption.

However, Russia, USA, Germany, France and the UK were all rated as 'medium risk' countries.

America's potential vulnerability to climate change was also highlighted by new research from the National Center for Atmospheric Research (NCAR), which suggested it was among many heavily populated countries facing a growing threat of severe and prolonged drought in the coming decades.

Using the Palmer Drought Severity Index (PDSI), where a reading of +0.5 to -0.5 indicates normal conditions and below -4 indicates extreme drought, researchers compiled computer climate models, previous studies and a comprehensive index of drought conditions to project that ratings in 2030 could drop to -6 in much of the central and western United States and -8 or lower in parts of the Mediterranean.

The study added that drought risks could reach unprecedented levels of -8 to -10 in the US and -15 to -20 in the Mediterranean by 2100.

Most of the Western Hemisphere, along with large parts of Eurasia, Africa, and Australia, could be at threat of extreme drought this century, the reports finds, although drought risk is expected to decrease across much of Northern Europe, Russia and Canada, as well as some areas in the Southern Hemisphere as climatic patterns shift.

"If the projections in this study come even close to being realised, the consequences for society worldwide will be enormous," said Aiguo Dai, who conducted the research.

The new studies come in the same week that the British government warned that climate change represents a growing threat to the country's security as part of its Strategic Defence and Security Review.

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